def sumOutVariable(factor, variable):
"""
Sum out a variable from a factor
"""
newVars = [x for x in factor.variables if x != variable]
varIndex = factor.variables.index(variable)
newF = Factor(newVars, mnCards)
if debug: newF.printF()
usedVar = [False for x in range(factor.size)]
for i in range(newF.size):
newF.phi.append(0)
start = 0
for k in range(factor.size):
if usedVar[k] == False:
start = k
break
for j in range(factor.card[varIndex]):
key = start + factor.stride[varIndex] * j
newF.phi[i] += factor.phi[key]
usedVar[key] = True
if debug: print "phi: ", i, " ", newF.phi[i]
return newF
def sumOutVariable(factor, variable):
"""
Sum out a variable for variable elimination
"""
if debug: print "eliminating factor"
newVars = [x for x in factor.variables if x != variable]
if debug: print "new vars: ", newVars
newF = Factor(newVars, mnCards)
if len(newVars) > 0:
varIndex = factor.variables.index(variable)
if debug:
print "var index: ", varIndex
newF.printF()
usedVar = [False for x in range(factor.size)]
if debug:
print "used var: ", usedVar
print "stride: ", factor.stride[varIndex], ", card: ", factor.card[varIndex]
psi = []
for i in range(newF.size):
psi.append(0)
start = 0
for k in range(factor.size):
if usedVar[k] == False:
start = k
break
for j in range(factor.card[varIndex]):
if debug: print "start: ", start, " stride: ", factor.stride[varIndex], " j: ", j
psi[i] += factor.phi[start + factor.stride[varIndex] * j]
usedVar[start + factor.stride[varIndex] * j] = True
if debug: print "psi: ", i, " ", psi[i]
newF.phi = psi[:]
return newF
